The field of art to which this invention pertains is synthetic resins obtained by the reaction of compounds containing more than one epoxy group with curing agents, particularly aliphatic amine curing agents.
Epoxide resins are well known compositions which have found a wide variety of uses and which have been reacted with a wide variety of curing agents to form cured compositions. Very useful curing agents are aliphatic amines. However, in some applications, epoxide resins cured with aliphatic amines are lacking in some desirable properties. Epoxide resin/aliphatic amine systems are deficient in low temperature cure response in that such system do not cure satisfactorily at temperatures below 40.degree. F. Also, such systems, especially at low temperatures, are viscous and do not properly wet to substrate to which they are applied. In addition coating made from epoxide resin/aliphatic amine curable compositions, when cured at room temperature under atmospheric conditions, often have greasy uneven surfaces. Finally, such systems, particularly in large masses, will undergo exothermic reactions which are difficult to control.
U.S. Pat. No. 3,383,434 discloses a curable system made from a diepoxide resin, an unsaturated polyester and a polyamine which has two primary amine groups. According to the patent, the disclosed system will react rapidly at low temperatures to give thermoset resins. The amine reacts with the C .dbd. C bond contained in the polyester as well as with the epoxy groups to form a complex cross-linked resin. Such systems are said to have short gel times and low peak exotherms. However, such systems are viscous and exhibit poor wetting properties.
U.S. Pat. No. 2,548,447 describes cold-setting adhesives made from expoxide resins diluted with a cyano-substituted hydrocarbon cured with a polyamine. Acetonitrile is the preferred diluent although acrylonitrile and methacrylonitrile are disclosed as being useful. Acrylonitrile and methacrylonitrile are monofunctional and volatile.
U.S. Pat. No. 2,939,859 discloses curable compositions made from a polyepoxide resin, sytrene and an epoxide resin curing agent plus, preferably, a peroxide catalyst. Styrene is monofunctional and volatile.